1. Field of the Invention
This invention relates broadly to surgical instruments. More particularly, this invention relates to endoscopic injection needle devices insertable into an endoscope.
2. State of the Art
An endoscopic injection needle is inserted through a lumen of a flexible endoscope to inject fluids under endoscopic visualization in such body structures as the esophagus, the colon, and the stomach. For example, during a colonic polypectomy, it is customary to inject saline solution into the tissue surrounding and underlying a polyp in order to "raise" the polyp to facilitate excision of the polyp by means of an endoscopic forceps or snares. Also, visible dyes and radiological contrast dyes are sometimes injected to mark the location of areas explored endoscopically so that the structures can be located during subsequent procedures. Additionally, sclerosing agents are sometimes injected into vascular structures, such as esophageal varicoceles, in order to cause clotting and to necrose the tissue so that it can be resorbed by the body.
The current art consists of several endoscopic needles marketed by companies such as Boston Scientific/Microvasive, Olympus, Wilson-Cook and others. Typically, the needle devices generally consist of an inner flexible tubing, usually made of polytetrafluoroethylene (PTFE), surrounded by a loose-fitting outer jacket made of PTFE, fluorinated ethylene propylene (FEP), or similar flexible plastic, a handle assembly at the proximal ends of the inner tubing and outer jacket, and a needle attached to the distal end of the inner tubing. A physician grips the outer jacket of the needle device with one hand to introduce it through a sealing port on the endoscope handle which communicates with the working channel of the endoscope and to position the distal end of the device proximate the desired tissue at the distal end of the endoscope. With his or her other hand, the physician holds the proximal handle of the endoscope so that the steering knobs on the endoscope handle can manipulated while viewing the endoscope image. The handle assembly of the endoscopic needle device is held and manipulated by an assistant, according to the oral commands of the physician. For example, the physician may manipulate the knobs of the endoscope to position the tip of the endoscope near (within a few millimeters of) a polyp. The physician then advances the outer jacket of the needle device into the endoscope handle until the distal end of the outer jacket approaches and touches the tissue surrounding the polyp. Then the physician orders the assistant to advance the needle, which the assistant does by operating a needle-advance function on the handle assembly of the needle device. Then the physician orders the assistant to inject fluid, which the assistant does by operating a syringe connected to the handle assembly of the needle device. The physician then orders the assistant to stop injecting and withdraw the needle. These operations complete one injection; typically, the physician injects several times around a polyp in order to achieve the desired results. Accordingly, the procedure takes a great deal of time and requires precise coordination between physician and assistant.